ML20235A631

Supplemental Application for Amend to License DPR-65, Revising Tech Spec Re Containment Sys Integrated Leak Rate Test.Fee Paid

ML20235A631
Person / Time
Site:	Millstone
Issue date:	01/05/1988
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20235A633	List: B12784, Proposed Tech Specs,Revising Integrated Leak Rate Test ML20235A631
References
B12784, NUDOCS 8801120369
Download: ML20235A631 (5)

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, (203) 665-5000 January 5, 1988 Docket No. 50-336 ]

B12784 Re: 10CFR50.90 U.S. Nuclear Regulatory Commission Attn: Document Control. Desk Washington, D.C. 20555

! Gentlemen: '

Millstone Nuclear Power Station Unit No. 2 Proposed Revision to Technical Specifications In a letter dated December 28, 1987(1) , Northeast Nuclear Energy Company (NNECO) submitted to the Staff a proposed change to the Millstone Unit No. 2 Technical Specifications relating to Con-tainment Systems. The purpose of this letter is to provide a supplemental change to the Technical Specifications, to be

. considered in concert with the previously submitted change.

Pursuant to 10CFR50.90, NNECO hereby proposes to amend its

. Operating License, No. DPR-65, by incorporating the change identified in Attachment 1 into the Technical Specifications of Millstone Unit No. 2.

BACKGROUND By letter dated December 23, 1987( ) , NNECO submitted a request for exemption pursuant to 10CFR50.12. The exemption request stated that ANSI N45.4-1972 requires that leakage calculations be performed using either the total time method or the point to point method. Since the issuance of ANSI N45.4-1972, a more accurate method of determining containment leakage rates, the mass point method, was developed as described in (1) E. J. Mroczka letter to U.S. Nuclear Regulatory Commission dated December 28, 1987, " Proposed Revision to Technical l Specifications, containment Systems."

(2) E. J. Mroczka letter to U.S. Nuclear Regulatory Commission, l

dated December 23, 1987, "10CFR50 Appendix J, Request for Exemption." '

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U. S. Nuclear Regulatory Commission B12784/Page 2 January 5, 1988 ANSI /ANS-56.8-1981, " Containment System Leakage Testing Require-ments." Therefore, NNECO requested an exemption to allow use of the mass point method for calculating containment luakage ratec.

Similar exemption requests have previously been approved NRC for Millstone Unit No. 1 and the Haddam Neck Plant, g the as well as other plants throughout the country. This amenduent request is identical in substance to the issue presented in the recent exemption request.

The previous exemption and this amendment request reflect the fact that more current methodologies are being used to calculate the containment leakage rate during the Integrated Leak Rate Test. This new methodology is not recognized in ANSI N45.4-1972; therefore, the requirement to use methods delineated by this ANSI Standard is proposed to be deleted from the Technical Specifications.

DESCRIPTION OF CHANGE The proposed change would delete reference to ANSI N45.4-1972 from Section 4.6.1.2 of the Millstone Unit No. 2 Technical Specifications.

A change is also proposed to Bases Section 3/4.6.1.2 to include the provision for use of the mass point method for performing leakage calculations.

SAFETY ASSESSMENT The present Technical Specifications include a reference to the provisions of ANSI N45.4-1972. Since MP2 desires to use the mass point methodologies in performing the ILRT during the current Millstone Unit No. 2 outage, it is proposed the reference to the

. ANSI N45.4-1972 standard be deleted from the Technical Specifica-tions.

The mass point method is a more accurate means of determining containment leakage rates. The total-time method calculates a series of time-weighted leakage rates, based upon differences between an initial data point and points occurring later in time.

, The adequacy of this method is sensitive to the initial data 1

(3) F. M. Akstulewicz letter to E. J. Mroczka, and M. L. Boyle letter to E. J. Mroczka, both dated October 15, 1987,

" Exemption From the Requirements of Appendix J to 10CFR50, Paragraph III.A.3."

U. S. Nuclear Regulatory Commission B12784/Page 3 January 5, 1988 between an initial data point and points occurring later in time.

The adequacy of this method is sensitive to the initial data point. Any perturbations, such as fluctuations in containment air temperature, ingassing or outgassing, or instrument error, can affect the' validity of the initial data point and downstream leakage calculations.

On the other hand, the mass point method calculai.es leakage rates based upon contained air mass. This technique accurately calcu-lates the mass of air inside containment and plots it as a function of time. The slope of the linear least squares fit of the data is the leakage rate. The use of this method is well-known and endorsed by ANS, EPRI and the NRC Staff.

SIGNIFICANT HAZARDS CONSIDERATION NNECO has reviewed the proposed change, in accordance with 10CFR50.92 and has concluded that it does not involve a signifi-cant hazards consideration in that this change would not:

1. Involve a significant increase in the probability or conse-quences of an accident previously evaluated. Removing the l reference to the 1972 ANSI Standard will allow more current and accurate methods to be used in determining the manner in which the ILRT test data are analyzed and statistically evaluated.

2. Create the possibility of a new or different kind of acci-dent from any previously analyzed. There are no failure modes associated with this change and therefore, there will not be a new, unanalyzed accident. ]

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3. Involve a significant reduction in a margin of safety. This is a Surveillance Requirement change, and there is no direct i impact on the boundaries or their safety limits. ]

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The Commission has provided guidance concerning the application I of standards in 10CFR50.92 by providing certain examples ]

(51FR7751, March 6, 1986). The changes proposed herein most  !

closely resemble example (1), a purely administrative change to l Technical specifications: for example, a change to achieve I consistency throughout the Technical specifications, correction of an error or change in nomenclature. NNECO considers this change to be enveloped by example (i), presuming issuance of the proposed exemption for Millstone Unit No. 2 based on discussions with the NRC Staff, and based upon the fact that identical ,

exemptions have recently been issued for the Haddam Neck Plant  !

and Millstone Unit No. 1. With the issuance of the requested {

exemption, this proposed change would serve to bring consistency  !

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U. S. Nuclear Regulatory Commission B12784/Page 4 January 5, 1988 i l

between Part 50 requirements (as amended by the exemption) and the Technical Specifications. The removal of the reference to ANSI N45.4-1972 reflects the current upgraded computerized approach which is consistent with the requirements of 10CFR50 Appendix J. and follows the guidance of ANSI 56.8-1981.

L ANSI /ANS 56.8-1981 and its 1987 revision, which was intended to replace ANSI N45.4-1972, specifies the use of the mass point method, to the' exclusion of the two older methods. However, the  !

staff has determined that these three methods (mass point, total time and point-to-point) are acceptable methods which may be used to -~ Iculate containment leakage rates. A proposed revision to Appendix J, which has been published for public comment (51FR39538, dated October 29, 1986), refers to a proposed Regula-tory Guide (MS 021-5, October 1986), which endorses, with excep-tions, the ANSI /ANS 56.8-1981 standard and the mass point method.

This rational has previously been utilized by the Staff in i approving mass point exemptions for the Haddam Neck Plant and Millstone Unit No. 1. I The Millstone Unit No. 2 Nuclear Review Board has reviewed and approved the attached proposed revision and has concurred with the above determinations. j With respect to the appropriate schedule for issuance of this amendment, we offer the following information. As described previously, the proposal herein is identical in substance to the exemption request of December 23, 1987. Accordingly, it could be argued that this amendment is merely clarifying in nature, and as such could be issued at your earliest convenience. We recognize that this approach would likely require some interim regulatory action. A more conservative view is that the amendment should be issued prior to entry into Mode 4 following the current refueling outage, since Mode 4 is the lowect mode applicability of the I 4

companion LCO to Surveillance RequL.ement 4.6.1.2. We believe this latter approach is the most desirable, and request your support in meeting this schedule. 4 The current schedule calls for entry into Mode 4 following i successful completion of the ILRT approximately February 15, j 1988. NNECO will continue to keep the Staff verbally informed of '

progress during the outage to the extent that this schedule could be altered.

In-accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment. ]

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U. S. Nuclear Regulatory Commission -

B12784/Page 5 January 5, 1988 Pursuant to the requirements of 10CFR170.12(c), enclosed with this amendment request is the application fee of $150. .

Very truly yours, NORTHEAST NGCLEAR ENERGY COMPANY f ff f s E. 'roczka' M p, Se ior Vice President STATE OF CONNECTICUT )

) ss. Berlin COUNTY OF HARTFORD )

Then personally appeared before me E. J. Mroczka, who being duly sworn, did state that he is Senior Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authorized to execute and file the foregoing information la the name and on behalf of the Licensee herein and that the statements contained in said information are true and correct to the best of his knowledge and belief.

W1/7 mea /)nlW Notary Pgli ic l

l 14 Comm.~ ion Expiros March 31,1988 cc: Kevin McCarthy Director, Radiation Control Unit Department of Environmental Protection Hartford, Connecticut 06116 W. T. Russell, Region I Administrator D. H. Jaffe, NRC Project Manager, Millstone Unit No. 2 W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos. 1, 2, and 3 I

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